Hello, I recently posted a few conceptual questions regarding conservation of momentum. I'm processing the information more easily now, but I've hit yet another bump in the road. I've learned that in an inelastic collision in which "velocity is the same before and after the collision" the velocity can be determined by dividing the initial velocity by the ratio of mnew:mold. In other words, mass and velocity are inversely proportional: http://www.physicsclassroom.com/class/momentum/Lesson-2/Using-Equations-as-a-Guide-to-Thinking (This is the animation): http://www.physicsclassroom.com/mmedia/momentum/fca.cfm But then, how is velocity the same before and after if it's obviously changing? And when would this situation of being able to find the new velocity by a simple ratio not work? Thanks, and I know this is going to be a very simple answer pointing out something I missed, but I'm just stumped :D.